Double gusseted bag with symmetrical valve



Oct. 29, 1957 E. LANDELL 2,811,301

DOUBLE GUSSETED BAG WITH SYMMETRICAL VALVE Filed Jan. 19, 1955 INVENTOR. ERNEST LANDELL.

ATIUANEKF.

Unite 7 States PatentD DOUBLE GUSSETED BAG WITH SYMMETRICAL VALVE Ernest Landell, Temple City, Calif., assignor to St. Regis Paper Company, New York, N. Y., a corporation of New York Application January 19, 1955, Serial No. 482,738

2 Claims. (Cl. 229-625) This invention relates to paper bags, and the features thereof, among other possibilities, are more particularly adapted for use in multiwall paper shipping sacks formed with pluralities of gussets at each side and preferably of the sewn-end valved type.

A very widely used type of multiwall gusseted sewnend paper valve bag is of the construction shown in patent to Bates et al., No. 1,752,292, granted April 1, 1930. While this type of valve bag has proven to be highly successful for its intended purposes, yet under some circumstances and for packing certain commodities, it is desirable to provide bags which have exceptionally wide gussets, and yet if such unusually wide gussets are provided, two serious difiiculties, among others, will arise. First, the manner of forming and folding in the valves in bags of this type is such that excessively large valves will necessarily result with such wide gussets, and secondly, at the non-valved corners, the inwardly directed folds of the gussets at the points where same are caught within the sewn seams at the ends of the bag will be spaced so far inwardly from the edges of the bag that when the bag is filled there will occur large re-entrant cavities of wasted space and also these gusset folds provide wrinkled strained areas of weakness which will tend to pull out from the sewn seam.

In accordance with the present invention, the abovenoted difiiculties heretofore encountered with wide gusseted sewn-end bags are overcome by providing the bags at each side edge with pluralities of gussets all of which, at the non-valved corners, may be secured by the sewn seams effectively at points close enough to the bag edges so that no portions of the gussets tend to pull out, and in conjunction with such multiple gussets, an improved valve construction is provided at the valve corner in such a way that the valve may be made of a reasonably limited size and which will still permit easy filling of the bag and secure closure of the valve, even though the total gusset width may be much greater than heretofore attempted in practice.

In my co-pending application Serial No. 480,198, filed January 6, 1955, and entitled Double Gusseted Bags, I have disclosed and claimed an improved multiwall paper bag construction having pluralities of gussets as aforesaid and also having a novel valve construction located primarily in one only of the pair of gussets at the valve corner. The present invention provides an alternative form of valve construction for use in a double gusseted bag in which the valve is located at a symmetrical position, that is to say, at the middle of the double gusset at the valve corner.

Other objects, features and advantages of the invention will appear from the more detailed description given below, taken in connection with the accompanying draw ings which form a part of this specification.

in the drawings:

Fig. 1 is a side elevational view partly in vertical section showing a valve corner of an empty bag made in accordance with the preferred form of the invention;

Fig. 2 is an end view of the construction shown in Fig. 1; and

Fig. 3 is a perspective view showing the valve corner of a bag according to the invention, in expanded condition and prior to the application of a closure means to the end of the bag.

As here shown, it will be understood that the figures illustrate one of the four corners of a bag, viz. the valve corner, whereas the other corners may (except for the double gusset formation) be of conventional form, for example as shown in said Bates et a1. patent. It will further be understood that generally bags involving the invention will be of a mulitply construction, although for clearness, only one ply is clearly indicated in the drawings. A pair of side-by-side gussets are shown at 10, 11 respectively; that is, gusset 10 is formed by two outwardly protruding creases or folds 12, 13 and an inner crease or fold 14, and similarly gusset 11 is formed by two outwardly protruding creases 13 and 15 and an inner crease or fold 16.

The term gusset as herein used is to be understood as meaning a formation such as is caused by creasing the paper as at 12, 13 and 14, that is, so that there will be an inwardly directed area of paper folded over at one inner gusset fold as at 14. The term double gusset as used herein is to be understood as having reference to the side-by-side joined pair of such gussets as shown at 10, 11.

In forming a multiwall bag with the valve corner as shown, superposed webs of paper may first be run through a conventional bag tubing machine to form a continuous multi-ply tube in the usual well known Way, except that instead of forming single gussets at the sides, double gussets are provided at each side, as indicated in the drawings. The continuous tube is then cut into bag lengths or blanks, each usually with so-called valve notch areas as at 17 at one corner which is to form the valve corner. That is, such notch construction initially comprises an extension of the gusset areas at the valve corner so that when such areas are turned in to form the valve, same will extend inwardly far enough to provide areas which will be caught in the sewn seam used to close the end of the finished bag and thereby afford extra strength against any danger that the valve will pop out of place or pull away from the stitches.

In order to form a valve on such a double gusseted bag length or blank, with the valve positioned symmetrically as shown, the paper areas at the end portions of the gussets are creased, shaped and folded as shown in Fig. 3. That is, the top corners of the outer walls of the two gussets are creased along diagonal fold lines as at 20 and 21 and folded inwardly. The span of the double gusset is creased horizontally as at 22 and the gusset areas above this line are folded inwardly to form'a valve flap. The gusset areas just below the line 22 receive a peculiar configuration whereby areas as indicated at 23, 24 may be folded inwardly respectively and ultimately to come in contact with the underside (inside surfaces) of valve flap areas 25, 26. To accomplish this, the portions of the middle gusset fold areas below the line 22 may be creased as best shown in Fig. 3, that is, so that there will be two inwardly directed triangular areas as at 27, 28 separated by a crease 13 which is a continuation of fold 13, but is directed inwardly instead of outwardly. Areas 27 and 28 join respectively portions of gussets 10 and 11 along outwardly directed crease lines 30 and 31. The upper portions of areas 27 and 28 join the areas 23 and 24 respectively along inwardly directed creases as at 32, 33. The upper outer portions of areas 23 and 24 respectively join portions of gussets 10 and 11 along inwardly directed creases 34, 35 which preferably are at 45 to the vertical 3 edges of the bag and at 90 to the diagonal fold lines 20, 21 above mentioned.

The upper portion of the center crease 13 of the double gusset forms (as shown at 13 in Fig. 3) the median line of the valve or valve flap, which'whe'n the "valve is collapsed (as shown in Fig. l) is located along the lower edge of the valve. The portion of what was initially a part of crease 13 and which was located between Crease portions 13' and 13" is identified at 13a, and as shown in Fig. 1, when the bag valve is in flat condition, this crease portion 13a extends along in under the lower edge 13 of the valve.

In Fig. 3, the gusset end portions, before being folded in to form the valve and as embodying the extended notch portions 17, are shown in dot and dash lines. When these portions are folded in along diagonal lines 20, 21 and the valve is collapsed or nearly collapsed, the various crease lines and parts will assume the positions shown in Figs. 1 and 2, wherein it will be noted that the center fold of the double gusset is in normal condition up to the point indicated at 36. But above that point, there is a relatively small re-entrant cavity 37 of downwardly directed or inverted arrow shape, formed by the triangular areas 27, 28 above described. This permits the middle portions of the double gusset to join the areas 23, 24 above described along defined crease lines without wrinking and at the same time permitting the center crease portion 13a to assume the position shown in Fig. 1.

After the valve is shaped, formed and partially collapsed as above described, there may be inserted therein a valve sleeve of any desired type for checking sifting of the contents out through the valve of the filled bag, for example, as shown, a sleeve of the tuck-in type as indicated at 38, having at its inner end a cuff of conventional form as shown and which is adhered astride the inner end edge of the valve flap. Such tuck-in sleeves are shown in U. S. Patent to Redington No. 1,754,769. If preferred, an inwardly directed type of sleeve, as shown in the patent to Contryman No. 2,378,285, may be used.

After the valve is formed and the sleeve is in place (if one is used), the flattened bag end may be closed by a sewn seam 'as at 40, accompanied if desired by an end closure tape of conventional form as at 4-1 which is folded over astride the bag end and retained by the seam.

Numerous important advantages of using for large thick bags in certain cases, double gussets in lieu of gussets of equivalent total width but comprising a single inward fold, are fully explained in my above-mentioned copending application. As there explained, these advantages are important at the non-valve corners. But as further explained, a deep gusset at a notched valve corner of bags of the sewn end type presents a very serious problem in that if the notch is to be cut in the conventional way on the bag tubing machine, then either the valve must be made of a very excessive depth or else in the process of cutting the notch portions, the areas which are to form the inturned valve flap will be cut away, with the result that the finished valve in use will not stay in place or form a good closure. On the other hand, if instead of a single deep gusset, a double gusset is used of equivalent total gusset width, then in the notch cutting step during the tubing operation, the notch may be cut in the conventional way for a valve of reasonably moderate size and without cutting away any of the desired areas of the inwardly protruding valve flap portion. That is, it will be apparent from inspection of Fig.3 that the areas at the region indicated at 42 originally occurred at the mid-portion of the gusset formation and if such areas extended far intosthe flattened tube, as would be the case with a deep single gusset, then such areas would be cut away in cutting the notch, if the valve is limited to a resonably moderate size. On the other hand, with a double gusset, the areas in the region indicated at 42 initially will be at the outwardly protruding middle fold line 13 and thus will escape being cut and removed during the normal notch-cutting step.

The valve and gusset structure shown in the drawings is so proportioned that for example the total double gusset width may be 8", whereas the valve may have a depth of about 5 /2 (as measured from the crease 13" up to the line of stitching). If a single deep gusset were used of a total expanded width of 8" and if the valve were made of this depth, then in the usual notch cutting operation in the tuber, the areas of valve flap material indicated at the region marked 42 in Fig. 3 will be cut away, thus providing an unsuitable valve flap.

In general with the double gusset in accordance with the present invention, the minimum valve depth (measured as above stated) maybe made equal to three-quarters of. the total gusset width, less about 2 8 to allow for clearances without danger of cutting into the inner end edge of the valve flap during the normal notch cutting operations. On the other hand, with a single deep gusset of comparable width, such minimum valve depth would be equal to the total gusset width less about /3", Stating the matter in another way, the dimension indicated at X in Pig. 3 may be made the same whether a single or double gusset is used, whereas with the double gusset, the dimension indicated at Y is limited by the normal notch-cutting step to not less than one-half of the total gusset width where a single gusset is used, but this dimension Y may be reduced to one-quarter of the total gusset width on a double 'gusseted bag (plus a small amount for clearance to avoid danger of cutting the valve lip).

It will be understood that when the bag is filled and the contents become crowded up into the top or peak of the bag, the valve will be shifted from the generally vertical fiat condition of Figs. 1 and 2 to a generally horizontal flattened position up within the top of the bag, similar to the valves of the above-mentioned Bates et al. patent. At that time the protruding end of the sleeve 38 (if a tuckin type sleeve is used) may be folded in according to known practice and the double gussets will have become expanded generally as indicated in the lower part of Fig. 2.

The valve construction is such that the various parts thereof will be symmetrical at all times with respect to the center crease 13 of the double gusset formation with the result that after the bag is filled, the valve corner, including the upstanding closure portions as well as both gussets, will prevent a symmetrical appearance with respect to a vertical plane through the center of the bag and parallel to its front and back wall surfaces. With such a symmetrical structure, all of the crease lines will be predetermined and free of irregular wrinkles, and then the valve makes possible a tight secure closure as fully effective as small valves width narrow gussets heretofore used, but avoiding the excessively large valves heretofore necessitated in similar bags having a single large gusset.

Although one embodiment of the invention is herein disclosed for purposes of explanation, various further modifications thereof, after study of this specification, will be apparent to those skilled in the art to which the invention pertains. Reference should accordingly be had to the appended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A paper valve bag formed of a tube length having at its side a pair of si e-by-side gussets, including an outwardly protruding middle fold portion common to said gussets, said portion at. the region below the valve corner having an inward fold forming a downwardly pointing arrow-shaped re-entrant cavity, the gussets just above said cavity having creases defining outwardly folded areas, and a valve flap extending into the bag at said .valve corner, the outer portion of said flap integrally joining the outer. edges of said areas along a fold line, the

two upper outer portions of the gussets respectively being folded inwardly along lines diagonally of the corner of the bag and forming portions of such valve flap.

2. A paper valve bag formed of a tube length having at its side a pair of side-by-side gussets, including an outwardly protruding middle fold portion common to said gussets, said portion at the region below the valve corner having an inward fold forming a downwardly pointing arrow-shaped re-entrant cavity, the gussets just above said cavity having creases defining outwardly folded areas, and a valve flap extending into the bag at said valve corner, the outer portion of said flap integrally joining the outer edges of said areas along a fold line, said valve flap having a median fold line located in the plane of said middle fold when the bag is fiat prior to filling.

References Cited in the file of this patent UNITED STATES PATENTS Bates et a1 Apr. 1, 1930 Redington Apr. 15, 1930 Belcher Feb. 18, 1947 Hartman Apr. 21, 1953 FOREIGN PATENTS Australia Mar. 18, 1927 Denmark Dec. 19, 1938 

